Messages in this thread Patch in this message | | | From | Borislav Petkov <> | Subject | [RFC PATCH v0 04/19] x86/insn-eval: Handle return values from the decoder | Date | Tue, 24 Nov 2020 11:19:37 +0100 |
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From: Borislav Petkov <bp@suse.de>
Now that the different instruction inspecting functions return a value, test that and return early from callers if error has been encountered.
Signed-off-by: Borislav Petkov <bp@suse.de> --- arch/x86/lib/insn-eval.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 99fafbaf8555..5825b4cf4386 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -1117,7 +1117,8 @@ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs, if (insn->addr_bytes != 8 && insn->addr_bytes != 4) return -EINVAL; - insn_get_modrm(insn); + if (insn_get_modrm(insn)) + return -EINVAL; if (!insn->modrm.nbytes) return -EINVAL; @@ -1125,7 +1126,8 @@ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs, if (X86_MODRM_MOD(insn->modrm.value) > 2) return -EINVAL; - insn_get_sib(insn); + if (insn_get_sib(insn)) + return -EINVAL; if (!insn->sib.nbytes) return -EINVAL; @@ -1194,8 +1196,8 @@ static void __user *get_addr_ref_16(struct insn *insn, struct pt_regs *regs) short eff_addr; long tmp; - insn_get_modrm(insn); - insn_get_displacement(insn); + if (insn_get_modrm(insn) || insn_get_displacement(insn)) + goto out; if (insn->addr_bytes != 2) goto out; @@ -1491,7 +1493,9 @@ bool insn_decode_regs(struct insn *insn, struct pt_regs *regs, insn->addr_bytes = INSN_CODE_SEG_ADDR_SZ(seg_defs); insn->opnd_bytes = INSN_CODE_SEG_OPND_SZ(seg_defs); - insn_get_length(insn); + if (insn_get_length(insn)) + return false; + if (buf_size < insn->length) return false; -- 2.21.0
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